Streaming media (e.g. audio and video) may be sent over packet networks such as the internet. Previous buffering schemes to handle the packets for packetized voice applications utilized a single jitter buffer which limits the number of voice paths which may be supported to a single path. Also, such buffering schemes require identical encoding and decoding schemes.
The jitter buffer function in a packetized voice application is to eliminate the variable inter-packet timing caused by the network a packet traverses. The jitter buffer's task is to collect enough packets to allow the slowest packets to arrive in time to be played out in the correct sequence. Some of the other more common features of a jitter buffer module are the detection of missing packets, detection of redundant packets, re-sequencing of packets (e.g. packets that arrived out of order will be rearranged and played out in the proper order).
Three-Way Calling (TWC) is a non-Centrex custom calling feature that allows one to add a third party to an existing telephone conversation without operator assistance. The procedure for setting up a three-way call is as follows:
1. Place your first call on hold by quickly pressing and releasing the receiver button (or use the Flash button)
2. You will hear a brief stutter tone. When you hear the dial tone, you can start dialing digits.
3. When the second called party answers, press and release the receiver button to connect all callers.
4. If the second called party does not answer or you reach a busy signal, push the receiver button twice to return to the first caller.
5. To end both calls, simply hang up.
6. To end the second call, push and release the receiver button, or wait for the second called party to hang up.
7. The first callers will end the original call when they hang up.
Call waiting feature informs a user already connected to a second party that another call is waiting. It does this by sending a burst of tone to the busy user. The busy station user may answer the new call by one of two methods. The busy station user may flash, placing the original call on hold and answer the new call, or the busy station user may go on-hook, in which case the station user is rung and connected to the new call upon answer. With flash a user can indefinitely switch between the second and third parties.
CW has the following main features:
1. Generation of tone for a period of time upon receiving a call from a third party.
2. If the controlling party does not flash or disconnect after the first burst of CW tone, a second burst of tone should be some time later.
3. If the controlling party answers the CW tone by going on-hook and remaining on-hook the controlling party should then be rung immediately.
4. If the controlling party answers the tone with a switch-hook flash (putting a party on hold) and subsequently goes on-hook and remains on-hook, the controller should be rung back immediately while the held party continues to be held.
5. If the held party disconnects, that party should be idled, and the talking parties should revert to a normal two-way connection. So a flash at this point will be interpreted as initiating a TWC.
A buffering scheme to handle multiple streams of packetized voice data related to the Call-Waiting (CW) and Three-Way Calling (TWC) widely available in most phone system plans is desirable.